Abstract: We discussed the correlate parameters of modifiers enhancing the hydrophilicity of the biofilm-substrate and promoting the mature of the membrane, which may provide references for their application in aquaculture wastewater treatment process. The silk net (aperture 0.425 mm) was chosen as the biofilm-substrate and six modifiers NaOH, Ca(OH)₂, HCl, KMnO₄, K₂Cr₂O₇, C₂H₅OH were tested as surface treatment reagents of substrate. The amount ofBacillus spp. adhered to substrate and the membrane-hanging effect in aquaculture wastewater provided some key evaluation indice for the six modifiers. The results show that compared with the other treatments, the substrate treated by 10% HCl for 6 h obtained the best hydrophilic ability and better membrane-hanging effect.